Opera glass



R. G. LESTER vMay 28, 1935.

OPERA GLASS Filed Sept. 15, 1955 v 2 Sheets-Sh eet 2 Vic Patented May 28, 1935 PATENT orrlcal OPERA GLASS Robert Gy. Lester, Chicago, Ill.

VApplication September 13, 1933, Serial No. 689,174

11 Claims.

The present invention relates generally to opera glasses. More particularly, the' invention relates to that type of opera glass which isadaptt ed to be folded or collapsed into an inoperative position for carrying or storing purposes and comprises (l) a, pair of complemental casingmembers which are arranged in-superposed relation and are hinged together at the front ends thereof sothat they may be swung to and from one another; (2) a plate which embodies a pair of laterally spaced object lenses and is pivotally mounted between the rear or distal ends of the casing-members so that it may be swung from an inoperative or Vfolded position between they two members to an operative position wherein it extends substantially transversely of the members after the latter have been swung apart; (3) a frame which embodies a pair of laterally spaced eye lenses and is mounted adjacent to the front or proximal ends ofthe casing-members so that it may be moved bodily to and from the'plate in order to focus the eye lenses with respect to the object lenses; and (Il) mechanism foreffecting adjustment of the frame with respect to the plate.

One object of the invention is to provide an opera glass of the aforementioned type' in which the plate between the rear or distal ends of the two superposed, complemental casing-members is pivotally suspended from the top casing-member and is connected to the sides of thebottom casing-member by pin and slot connections so that when it is swung from its inoperative' or folded position between the two members into its operative position it automatically swings the bottom casing-member away fromlthe top `meinber, and when it is swung from its operative position wherein it extendsl substantially transversely of the two members `into its inoperative or folded position it operates automatically to swing the bottom casing-member into its inoperative position against the topmember.`

Another object of the invention' is to provide an opera glass of the aforementioned typen and character in which theframe' having the eye lenses is mounted in a bracket which is secured fixedly to, and is disposed within, the front end of the top casingmeinber and is arranged so that it holds the frame in an angular ornon-parallel position with respect tothe top casing-member and so that the `ey'e lenses are properly aligned and centered with respect-to the Lobject lenses when the plate between the rear or distal ends of the two casing-members is swung from its inoperative or folded position into its operative (oli. vsis-a5) position wherein itgextends transversely of the members.

A further object of the invention is to provide an opera glass which is generally an improvement upon previously designed glasses of the same general character and type, consists of' but a small number of parts andmay be manufac` tured at a lowV and reasonable cost.

Other objects of the invention and the various advantages and characteristics of the present opera glass construction will be apparent froma consideration of the following detailedde'cript'ion.

The invention consists in the several novel feathe glass being shown in their folded or collapsed position;

Figure 2 is a perspective showing the glass in its operative position, that is, `in the position wherein the casing-members are swung apart and the plate withthe object lenses extends transversely with respect'to the casing-members; i Figure 3 is a vertical section showingin detail the construction and arrangement of fthe frame Y for the eye lenses and the mechanisniformov ing the frame to and fromthe object lenses for focusing purposes, the casing-membersand plate being shown in their closed position; l

Figure 4 is a vertical section showing 'the `cas ing-members swung apart into their operative position and illustrating the manner in which the bracket supports the frame with the eye lenses so that the frame is angularly disposed with respect to the top casing-member and the eye lenses are centrally disposedwithrespect 'to the object Vlenses whenV the plate with the object lenses is swung into its operative position;-

Figure 5 is a vertical section illustrating indetail the manner in which the two complemental casing-members are hinged together at-the front ends thereof, and showing the construction and arrangement of the pin and slot connections between the plate and the bottom casing-member; Figure 6 is a vertical section-showingthe con struction and arrangement of the lenses of the opera glass; l

Figure "I is va horizontal sectionv on the line 1-1 of Figure 6;

Figure 8 is a perspective of the plate which is equipped with the object lenses;

Figure 9 is a perspective of the frame for the eye lenses;

Figure 10 is a perspective of the bracket which is connedin the lfront end of the top casingmember and supports the frame with the eye lenses for movement to and from the object lenses; and

Figure 11 is a perspective of the bottom casingmember. V y

The opera glass which forms the subject matter of the present invention comprises as the major parts thereof a top casing-member I2, a bottom casing-member I3, a plate I having a pair of object lenses I and a frame lihaving a pair of laterally spaced eye lenses.

The top casing-member I2 overlies the bottom member I3. It is formed from a sheet metal blank, consists of a top wall I8, a front wall is, aV rear wall 20 and a pair of side walls ZI. The side walls 2! are formed integrally with and depend'fromthe side margins of the top wall i8, as shown. particularlyv in Figures 1 and 2 of the drawings, and are cut away at the rear lower cornersv thereof so as to accommodate the bottom casing-member I3.k The front wall I9 is formed integrally with and depends from the front margin of the top wall I8 of the top casing-member I2, and is joined at the ends thereof to the conn tiguous Yfront edges of the side walls 2i. The bottom margin of the front wall l is provided with anV extension 22 which, as shown in Figures 3, 4, 5, and 6, is bent inwardly so that it extends parallel with the top wall I8 and under the front ends of the side walls 2! and forms with the lat` 'ter andthe front wall I9 a compartment 23 at the'front end of the top casing-member I2. The rear wall 20 is formed integrally with and de- Vpends from the rear margin of the top wall i8 and is joined at the ends thereof to the contiguous rearedges ofthe side walls 2i The bottom casing-member I3 is in the nature of a complement of the top casing-member I2. It is formed from a sheet metal blank and consistsof a bottom wall 24, a rear wall 25 anda pair of'side wallsV 26. The'rear wall 25 is formed integrally with and extends upwardly from the rear margin of the bottom wall 24. The side walls 2S are formed integrally with and project upwardly from Ythe side margins of the bottom wall 2li and are joined at the rear ends thereof to the contiguous end edges of the rear wall 25. The front ends of the side walls 26 of the bottom casingmember I3 are extended to form tongues 27 which project forwardly of the iront margin oi the bottomwall 24. These tongues, as shown in Figure 1l, are inwardly offset with respect to the side walls 26 and lap the inner faces of the front ends of the side walls 2| of the top casing-member I2. Rivets 28 extend through the tongues 2l and the frontA ends of the side walls of the top casingV member and form with the tongues a pail` of pivotal connections whereby the bottom casingmember I3 is hinged at its front endv to the front end of the top casing-member I2 so that it is free to be swung to and from the top casing-member. When the two casing-members are swung tcgether as Vshown in Figures l, 3 and 5, the side walls 26 ofY the bottom easing-member fit within the spaces which are formed as the result of cutting away the lower rear corners of the side walls of the top casing-member. YThe side walls of the vbottom casing-member are coplanar with the side walls of the top casing-member andthe pivotal or hinge connections between the tongues 27 and the side walls of the top casing-meznber are such that when the two members are swung together the bottom wall 255 of the bottom casing-member I3 is coplanar with the extension 22. The rear wall 25 of the bottom casing-member fits against and is coplanar with the rear wall 20 of the top casing-member when the two members are swung together, as shown in Figures l, 3 and 5. In order releasably to hold the two casing-members together, a latch 29 is provided. This latch consists of a spring strip which is applied to the rear wall 25 of the bottom casingmember I3 and is arranged so that it overiies the top wall 2i! of the rear casing-member when the two members are swung together. A stud Si is formed on the outer or free end of the spring strip 30 and. lits Within a pawl :'32 in the rear wall 2B of the top casing-member so as to lock the two members together. When it is desired to swing the casing-members apart, the stud is removed from the hole 32 by swinging outwardly the spring strip 38.V When the casing-members are swung together, the stud Si because or" the action of the spring strip B, snaps into the hole 32 and thus effects a secure locking together of the two casing-members.

The plate i@ which carries or is equipped with the object lenses I5 is formed from a rectangular blank of sheet metal and is provided with integral, inturned flanges 33 at the ends thereof. It embodies a pair of laterally spaced, circular apertures 34 for the object lenses I5 and is pivotally suspended from the rear end of the top casingmember I2 by pivot pins 35. The latter extend through the rear ends of the side walls 2l of the casing-member and the-upper ends of the .inturned anges 33 at the ends of the plate ill and permit the plate to be swung from an operative position wherein it extends transversely with respect to the casing-members into a folded or inoperative position wherein it is disposed between the two members. The lower ends of the inturned flanges 33 are provided with outwardly extending pins 36. The latter extend through and slide longitudinally in elongated slots 3l' in the side walls 25 'of the bottom casing-member iand coaet with the slots 'so as to cause automatically the bottom casing-member to be swung .awayv from the top casing-member, and also to cause the bottom casing-member to be swung automatically towards the top casing-member when the plate is swung into its folded or inoperative position under the rear end of the top casing-member. er ends of the pins 36 are preferably in the form of knobs so that they may be gripped by the user of the opera glass in connection with swinging the plate I 4 into and out of its operative position. The object lenses I5 are of slightly larger diameter than the apertures Maud are held in place against the front face of the plate lli and in registry with the apertures 3ft by bottom tongues 33 and top tongues 39. The bottom tongues 38 are formed integrally with the portions of the plate i6 which deiine the lower parts of the apertures 3G, and underlie and support the bottom portions of the object lenses i5. The top tongues 35 are cutfrom the upper margin of the plate Ill and are bent around the front upper portions of the object lenses i5 so as to hold them in a seated position with respect to the apertures 34. There are preferably two of the bottomtongues 38 for each object lens and but a single top tongue 39 is needed for each lens. By employing the tongues 38 and 39, the object lenses are held `inseated the lens-retaining barrels 49.

relation with the apertures 34 ina simplezand in expensivamanner. l

Thefframe iwhich carries or is equipped with theI eye. lenses il: is located in the. compartment 23. It is preferably in the nature or form of a die' casting and consists of a pair of lens-retainingV barrels 4i!` and a crossbar 4I. The crossbar extends between and is `formed integrally with the central portions of the barrels and serves to hold the barrels inlaterally spaced relation. The portions of the barrels'in front of the crossbarrli are'preierably` larger than the portions in back of or at the rear of the crossbar. They are cylindrical' in form and extend through circular apertures4?. in the front wall IS of the top casing member i2. The extreme. front ends of the bar rels are recessed or bored to form annular seats 4%`v forr the eye lenses il. The latter are staked, cemented. or otherwise secured in the seats and are adapted torbe aligned Vwith the object lenses I when the plate I4 is swung into its operative position. The barrels is are hollow, as shown in Figure. The frame it is supported by a bracket 44 so that it is movable bodily to and from the plate I4 in order that the eye lenses I'i may be brought into focus with the object lenses I5. The bracket 44 is formed from a strip of metal and eX- tends transversely across the central portion of the compartment 23 in the front end of the top casing-member i2. The ends of the bracket are bent so that they extend rearwardly at right angles to the central portion of the'bracket and are secured to the side walls 2i of the top casingmember by means of the rivets 28. The central portion ofthe bracket is provided with a pair of apertures 45. These apertures are aligned with the apertures 42 in the front wall I9 of the casing member and receive slidably the rear portions or By virtue of the factthat the front portions of the barrels 4I) eX- tend through the circular apertures 42 in the front wall Id of the top casing-member and the rear portions of the barrels are mounted slidably in the circular apertures 45 in the central Aportion of thebraoket 44, the frame' l is mounted so that it is shiitable bodily toand from the plate I4 for focusing. purposes. The bent ends of the bracket 44 are arranged so that the central portion ofthe bracketis held at such an angle with respect to the top wall iii ci the top casing-member l2 that the lens-retaining barrels 40 of the frame i6 are centered and aligned with the object lenses i5 when the plate I4 is in its operative position. The front wall I9 of the top casing-member extends parallel with the central portion of the bracket 44 with the result' that the barrels 4i!` extend at right angles thereto. Because the frame i6 is held by the bracket in an angular position with respect to the top wall I8 of' the topcasing-mernber instead of parallel with the top wall; the rear portions of the barrels 4Q are cut away on the under portions thereof as at 46 in order to t against the extension 22 ofthe front wall of the top casing-member.

In addition to thetop and bottom casing-members, lthe plate i4, the frame i6 and the bracket 44, the opera glass comprisesmechanisrn for adjusting the fra-me it to and from the plate I4. This mechanism consists of a screw 41 and a nut 48. The screw 4l is secured xedly to and projects rearwardly from the central portion of the crossbar 4I of the frame i5 and extends through ahole 49 in the central portion of the bracket 44. The nut 48 is mounted on the screw 4'! and is located in a pocket 50 which is formed between 44v and a Ueshaped metal` strip 5i.

thefrear faceof the central portion of the bracket The legs of this stripzarevprovided with outturned flanges 53 which are spot welded to the central portion of the bracket 44. A washer 54 ts between the nut 48. and the rear face of the bracket 44 and a vwasher 55 fits between the nut and the strip 5I. These washers are mounted on the screw 47- and serve to hol-d the nut 48 against axial displacement in the pocket 5D. The top wall i8 andv extension 22 of the top casingmember i2 are slotted so that the nut 48 is accessible from the outside of the casing-member. When the nut is turned in oneY dir-ection, the frame iii is-shifted away from the plate I4 and when the nut is rotated in the opposite direction, the frame is shifted towards the plate I4. By turning the nut, the frame may be adjusted in order t-obring the eye lenses I'I into focus with the object lenses I5 on the plate I4.

When the opera glass is to be used, the spring strip of the latch 2S is swung outwardly so as to withdraw the studI from the pawl 32 in the rear wall 2G oi the top casing-member I2. Thereafter, the plate i4 is swung downwardly from its folded or collapsed position under the top casing-rnernberA I2 until it is arrested as the resultof the pins 36 striking against the rear ends of the slots 37. As the plate i4 is swung downwardly, the bottom casing-member i3 isautomatically swung away from the top casing-member in response to the action of the pin and slot connections between the plate and the bottom casing-member. When the plate I4 is in its operative position, the glass may be used by looking through the eye lenses I1 in the barrels 4t of the frame IE. In the event that the eye lenses are not properly focused, an ad.- justment may be effected by manipulation of the nut 48. When it isI desired to collapse the glass, the plate I4 is swung upwardly under the top casing-member i2 into its inoperative position. During upward swinging movement of the plate i4, the bottom casing-member I-B is swung up wardly against the rear end of the top casing member in response to the action of the pin and slot connections between the plate i4 and `the side walls 2li of the bottom casing-member. The herein disclosed opera glass consists of but a small number of parts and may be manu iactured at a low and reasonable cost. It is extremely compact and when in its folded or collapsed position, occupies but a small space.

Whereas the glass has been defined as an opera glass, it is to be understood that it may be used as a iield glass and for different purposes. It is also to be understood that the invention is not to be restricted to the details set forth, since these may be modified within the scope of the appended claims, without -departing from the spirit and scope `of the. invention.`

Having thus described the invention, what I claim as new and desire to secure by Letters Patent, is:

l. An opera glass of the character described, comprising in combination -a pair of complemental casing-members arranged in superposed relation and hinged together at the front en-ds thereof so that they may loe swung to and from one another, a plate with objective lenses `mounted thereon connected pivotally to the rear end o one of the casing-members and adapted to be swung from a folded position between the two members into an operative position wherein it extends substantially transversely of the mem- Cil bers and vice versa, a pin and slot connection between the plate and the other casing-member whereby said other casing-member is caused automatically to be swung away from sai-d one casing-member when the plate is swung into its operative position and is also caused automatically to be swung towards said one casing-memberwhen the plate is swung into its folded position, and eye lenses at the front ends of the casing-members arranged. so that they are aligned and centered with the object lenses when the plat-e is in its operative position. 2. An opera glass of the character described, comprising incombination a pair of complemental, superposed casing-members provi-ded with side walls and hinged together at the front en-ds thereof so that they may be swung to and from one another, a plate with objective lenses mounted thereon connected pivotally to the rear ends of the side walls of one of the casing-inembers and adapted to be swung from a folded position between the two casing-members into an operative position wherein it extends sub-- stantially transversely of the two members and vice versa, pin and slot connections between the plate and the side walls of the other casingmember whereby said other casing-member is caused automatically to be swung away from said one casing-member when the plat-e is swung into its operative position and is also caused automatically to be swung towards the one member into a closed position when the plate is swung into its fold-ed position, and eye lenses at the front ends of the casing-members arranged so that they are aligned and centered with the object lenses when the plate is in its operative position. Y

3. An opera glass of the character described, comprising. in combination a pair of complemental casing-members arranged in superposed relation and hinged together at the front ends thereofso that they may be swung to and from one another, one of said members being provided with side walls having elongated slots therein, a plate with objective lenses mounted thereon connected pivotally to the rear end of the other casing member and adapted to be swung from a folded position between the casing members into an operative position wherein it extends substantially transversely of the two members and vice versa,` studs on the plate extending through and slidable in the slots in the side walls of said one Casing-member and forming with said slots connections whereby said one 2 casing-member is caused automatically to be swung away from the other casing-member when the plate is swung into its operative position and is also caused to be swung automatically towards said other casing-member into a closed position when the plate is swung into its folded position, and eye lenses at the front ends of th-e casing-members arranged so that they are aligned and centered with the object lenses when the plate is in its operative position.

4l. An opera glass of the character described, comprising in combination a pair of complemental, superposedl casing-members provided with side walls and hinged together at the front ends thereof so that they may be swung to and from one another, a plate with objective lenses mounted thereon suspended pivotally from the rear ends of the side walls of the top casingmember and adapted to be swung from a folded position between the casing-members into an operative position wherein it extends substantially transversely of the two members and vice versa, outwardly extending studs on the distal portion of the plate extending through and slidable in elongated slots in the side walls of the other casing-member and forming with the slots connections whereby the bottom casing-member is caused automatically to be swung away from the top casing-member when the plate is swung into its operative position and is also caused automatically to be swung t- Wards the top member and into a closed position when the plate is swung into its folded position, and eye lenses at the front ends of the casing-inembers arranged so that they are aligned and centered with the object lenses when the plate is in its operative position.

5. An opera glass of the character described, comprising in combination a pair of superposed casing-members, one of said members having rigid therewith a front wall with a pair of laterally spaced apertures therein and the other member elng in the form of a complement and hinged at its front end to the front end of the one member so that it is free to swing to and from the latter, a plate with a pair of objective lenses supported in laterally spaced relation thereon mounted pivotally between the rear ends the casing-members and upon swinging apart of said members to be swung from a folded or collapsed position between the members into an operative position wherein it extends at slightly less than right angles to said members, a frame disposed adjacent the front ends of the casing-members and embodying a pair of barrels provided with eye lenses therein and having the front ends thereof extending through the apertures in said front wall, and means iixedly connected to said one casing member and arranged to support the frame so that it is shiftable to and from the plate for focusing purposes and so that the barrels thereof are disposed at all times at such a constant or fixed acute angle with respect to said one casing member that the eye lenses are aligned and centered with the object lenses respectively when the plate is in its operative position.

6. An opera glass of the character described, comprising in combination a pair of superposed casing-members, one of said members having rigid therewith a front wall with a pair of laterally spaced apertures therein and the other member being in the form of a complement and hinged at its front end to the front end of the one member so that it is free to swing to and from the latter, a plate with a pair of objective lenses supported in laterally spaced relation thereon Y mounted pivotally between the rear ends of the casing-members and adapted upon swinging apart of said members to be swung from a folded or collapsed position between the members into an operative position wherein it extends at slightly less than right angles to said members, a frame disposed adjacent the front ends of the casing members and embodying a crossbar directly behind the aforesaid front wall and a pair of lens-equipped barrels mounted on the crossbar and having the front ends thereof extending through the apertures in said front wall, and a bracket connected xedly to said one casing-member and arranged to support the frame so that it is shiftable to and from the plate for focusing purposes and so that the barrels thereof are disposed at all times at such .a constant `or fixed acute angle with respect to said one casing member that the lenses therein are aligned and centered with the object ,lenses respectively when the plate is: in its operative position.

7. An opera glass of the character described, comprising in combinationa pair of superposed casing-members, one of said members having rigid therewith a pair of side walls and a front wall with a pair of laterally spaced apertures therein and the other member being in the form of va complement and hinged at its front end to the front end of the one member'so that it is free to swing to and from the latter, a plate with a pair of Y objective lenses supported in laterally spaced relation thereon mounted pivotally between the rear ends of the casing-members and adaptedupon swinging apart of said members to be swung from a folded or collapsed position between the members into an operative position wherein it extends at slightly less thanright angles to said members, a frame disposed adjacent to the front ends of the casing-members and comprising a crossbar in back of the aforementioned front wall and a pair of lens-equipped barrels mounted on the Acrossbar and having the front ends thereof extending through the apertures in said front wall, and a bracket having endparts connected xedly to the side walls of said one casing member rand also having a pair of apertures therein aligned respectively with the apertures in the front wall and arranged to receive slidably the rear ends of the barrels respectively and in such relation with respect to the apertures in the front wall that the frame is supported to slidev bodily to and from the plate for lens-focusing purposes and the barrels are disposed at all times at such a constant or fixed acute angle with respect `to said one casing member that the lenses inthe barrels are aligned and centered with the object lenses of the plate when the latter is in its operative position.

8. An opera glass of the character described, comprising in combination a pair of superposed, sheet metal casing members, one of said members having the front end thereof bent downwardly to form a front wall and then inwardly to form an extension adjacent the front .wall and the other member being in the form of a complement and hinged at its front end to the front end `of said one casing-member so that it is free to swing to and from the latter, a plate with a pair of objective lenses supported thereon mounted pivotally between the rear ends of the casingmembers and adapted upon swinging apart of said members to be swung from a folded or collapsed position between the members into an operative position wherein it extends at slightly less than right angles to said members, a frame 'confined in the front end of said one casingmember by the front wall and extension and comprising a crossbar positioned in back of said front wall and a pair of lens-equipped barrels mounted on the crossbar and having the front ends thereof extending through apertures in said front wall, and a fixedly mounted bracket confined in the front end of said one casing-member together with the frame and arranged to support the frame so that it is shiftable bodily to and from the plate for focusing purposes and the barrels are disposed at all times at such a constant fixed acute angle with respect to said one casing member that the lenses therein are aligned and centered with the object lenses when the plate is in its operative position.

9, An opera glass of the character described comprising `in combination a pair of ,complemental casing-members arranged in superposed relationand hinged togetherat the frontends thereof so,V that they maybe swung to and from l one another, a plate with la pair of object lenses supported in laterally spaced' relation thereon mounted pivotally between the rear ends of the casing-members and adapted upon swinging apart of said members to be swung from a folded or collapsed position between the members into an operative position wherein it extends at slightly less than right angles to said members, a front wall having a pair of laterally spaced apertures therein and connected rigidly to the front end of one of said members and at such an angle relatively tothe latter that it extends parallel to the plate when the latter is in its operative position, and a pair of eye lenses associated with the aforesaid apertures respectively and heldin `such a fixed angular position with respect to said one casing-member that they are aligned and centered with the object lenses respectively when the plate is in its aforesaid operative position.

l0. An opera glass of the character described comprising in combination a pair of complemental casing-members arranged in superposed relation and hinged together at the front ends thereof so that they may be swung to and from one another, a plate with object lenses supported thereon in laterally spaced relation mounted pivotally between the rear ends of the casingmembers and adapted upon swinging apart of said members to be swung from a folded or collapsed position between the members into an operative position wherein it extends at slightly less'than right angles to said members, a front wall having a pair of laterally spaced apertures therein and connected rigidly to the front end of one of said members and at such an angle relatively to the latter that it extends parallel to the platewhen the latter is in its operative position, a frame disposed adjacent the front ends of the casing-members embodying a pair of barrels provided with eye lenses therein and having the lfront ends thereof extending through lthe apertures in said front wall, and means secured xedly to said one casing-member and arranged to support the frame so that it is shiftable to and from the plate for focusing purposes and the barrels thereof are disposed at all times at such a constant or fixed acute angle with respect to said one casing-member that'the eye lenses are aligned and centered with the object lenses respectively when the plate is in its operative position. Y

l1. An opera glass of the character described comprising in combination a pair of superposed casing-members, one of said members having at the front end thereof a rigid front wall with an inwardly extending extension and the other member being in the form of a complement and hinged at its front end to the front end of the said one casing-member so that it is free to swing `to and from the latter, a plate with a pair of object lenses supported thereon mounted pivotally between the rear ends of the casingmembers and adapted upon swinging apart of said members to be swung from a folded or collapsed position between the members into an operative position wherein it extends at slightly less than right angles to said members, a frame confined in the front end of said one casingmember between the front wall and extension and embodying apair of lens-equipped barrels having the front ends thereof extending slidably through apertures in said front Wall, anda fixedly mounted'bracket also conned in the front end of said one casing-member between the front Wall and extension and arranged to support the frame so that it is shiftable bodily to and from the plate for focusing purposes and the barrels are disposed at al1 times at such a constant or xed acute angle with respect to said one casingmember that the lenses therein are aligned and centered With the object lenses when the plate is in its operative position.

' ROBERT G. LESTER. 

